In an effort to develop a broadly applicable approach to the facile one-pot synthesis of
oligosaccharides, the reactivity of a number of p-methylphenyl thioglycoside (STol) donors which are either
fully protected or have one hydroxyl group exposed has been quantitatively determined by HPLC. We have
characterized and quantified the influence on reactivity of the structural effects of different monosaccharide
cores and different protecting groups on each glycoside donor. In addition, we have established a correlation
between glycosyl donor reactivity and the chemical shift of the anomeric proton by 1H NMR. Using the reactivity
data, we have created a database of thioglycosides as glycosyl donors and demonstrated its utility in the easy
and rapid one-pot assembly of various linear and branched oligosaccharide structures. In addition, we have
developed the first computer program, OptiMer, for use as a database search tool and guide for the selection
of building blocks for the one-pot assembly of a desired oligosaccharide or a library of individual
Postmenopausal osteoporosis, a global public health problem, has for decades been attributed solely to declining estrogen levels. Although FSH levels rise sharply in parallel, a direct effect of FSH on the skeleton has never been explored. We show that FSH is required for hypogonadal bone loss. Neither FSHbeta nor FSH receptor (FSHR) null mice have bone loss despite severe hypogonadism. Bone mass is increased and osteoclastic resorption is decreased in haploinsufficient FSHbeta+/- mice with normal ovarian function, suggesting that the skeletal action of FSH is estrogen independent. Osteoclasts and their precursors possess G(i2alpha)-coupled FSHRs that activate MEK/Erk, NF-kappaB, and Akt to result in enhanced osteoclast formation and function. We suggest that high circulating FSH causes hypogonadal bone loss.
Upland cotton (Gossypium hirsutum) is the most important natural fiber crop in the world. The overall genetic diversity among cultivated species of cotton and the genetic changes that occurred during their improvement are poorly understood. Here we report a comprehensive genomic assessment of modern improved upland cotton based on the genome-wide resequencing of 318 landraces and modern improved cultivars or lines. We detected more associated loci for lint yield than for fiber quality, which suggests that lint yield has stronger selection signatures than other traits. We found that two ethylene-pathway-related genes were associated with increased lint yield in improved cultivars. We evaluated the population frequency of each elite allele in historically released cultivar groups and found that 54.8% of the elite genome-wide association study (GWAS) alleles detected were transferred from three founder landraces: Deltapine 15, Stoneville 2B and Uganda Mian. Our results provide a genomic basis for improving cotton cultivars and for further evolutionary analysis of polyploid crops.
Signal transducer and activator of transcription 3 (STAT3) is a key transcriptional mediator for many cytokines and is essential for normal embryonic development. We have generated a unique strain of mice with tissue-specific disruption of STAT3 in bone marrow cells during hematopoiesis. This specific STAT3 deletion causes death of these mice within 4 -6 weeks after birth with Crohn's disease-like pathogenesis in both the small and large intestine, including segmental inflammatory cell infiltration, ulceration, bowel wall thickening, and granuloma formation.
The mechanism by which nutrient status regulates the fusion of autophagosomes with endosomes/lysosomes is poorly understood. Here, we report that O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) mediates O-GlcNAcylation of the SNARE protein SNAP-29 and regulates autophagy in a nutrient-dependent manner. In mammalian cells, OGT knockdown, or mutating the O-GlcNAc sites in SNAP-29, promotes the formation of a SNAP-29-containing SNARE complex, increases fusion between autophagosomes and endosomes/lysosomes, and promotes autophagic flux. In Caenorhabditis elegans, depletion of ogt-1 has a similar effect on autophagy; moreover, expression of an O-GlcNAc-defective SNAP-29 mutant facilitates autophagic degradation of protein aggregates. O-GlcNAcylated SNAP-29 levels are reduced during starvation in mammalian cells and in C. elegans. Our study reveals a mechanism by which O-GlcNAc-modification integrates nutrient status with autophagosome maturation.
A B S T R A C T PurposeTo evaluate induction chemotherapy with docetaxel, cisplatin, and fluorouracil (TPF) followed by surgery and postoperative radiotherapy versus up-front surgery and postoperative radiotherapy in patients with locally advanced resectable oral squamous cell carcinoma (OSCC).
Patients and MethodsA prospective open-label phase III trial was conducted. Eligibility criteria included untreated stage III or IVA locally advanced resectable OSCC. Patients received two cycles of TPF induction chemotherapy (docetaxel 75 mg/m 2 on day 1, cisplatin 75 mg/m 2 on day 1, and fluorouracil 750 mg/m 2 on days 1 to 5) followed by radical surgery and postoperative radiotherapy (54 to 66 Gy) versus up-front radical surgery and postoperative radiotherapy. The primary end point was overall survival (OS). Secondary end points included local control and safety.
ResultsOf the 256 patients enrolled onto this trial, 222 completed the full treatment protocol. There were no unexpected toxicities, and induction chemotherapy did not increase perioperative morbidity. The clinical response rate to induction chemotherapy was 80.6%. After a median follow-up of 30 months, there was no significant difference in OS (hazard ratio [HR], 0.977; 95% CI, 0.634 to 1.507; P ϭ .918) or disease-free survival (HR, 0.974; 95% CI, 0.654 to 1.45; P ϭ .897) between patients treated with and without TPF induction. Patients in the induction chemotherapy arm with a clinical response or favorable pathologic response (Յ 10% viable tumor cells) had superior OS and locoregional and distant control.
ConclusionOur study failed to demonstrate that TPF induction chemotherapy improves survival compared with up-front surgery in patients with resectable stage III or IVA OSCC.
Sonication-induced silk hydrogels were previously prepared as an injectable bone replacement biomaterial, with a need to improve osteogenic features. Vascular endothelial growth factor (VEGF165) and bone morphogenic protein-2 (BMP-2) are key regulators of angiogenesis and osteogenesis, respectively, during bone regeneration. Therefore, the present study aimed at evaluating in situ forming silk hydrogels as a vehicle to encapsulate dual factors for rabbit maxillary sinus floor augmentation. Sonication-induced silk hydrogels were prepared in vitro and the slow release of VEGF165 and BMP-2 from these silk gels was evaluated by ELISA. For in vivo studies for each time point (4 and 12 weeks), 24 sinus floors elevation surgeries were made bilaterally in 12 rabbits for the following four treatment groups: silk gel (group Silk gel), silk gel/VEGF165 (group VEGF), silk gel/BMP-2 (group BMP-2), silk gel/VEGF165/BMP-2 (group V+B) (n=6 per group). Sequential florescent labeling and radiographic observations were used to record new bone formation and mineralization, along with histological and histomorphometric analysis. At week 4, VEGF165 promoted more tissue infiltration into the gel and accelerated the degradation of the gel material. At this time point, the bone area in group V+B was significantly larger than those in the other three groups. At week 12, elevated sinus floor heights of groups BMP-2 and V+B were larger than those of the Silk gel and VEGF groups, and the V+B group had the largest new bone area among all groups. In addition, a larger blood vessel area formed in the remaining gel areas in groups VEGF and V+B. In conclusion, VEGF165 and BMP-2 released from injectable and biodegradable silk gels promoted angiogenesis and new bone formation, with the two factors demonstrating an additive effect on bone regeneration. These results indicate that silk hydrogels can be used as an injectable vehicle to deliver multiple growth factors in a minimally invasive approach to regenerate irregular bony cavities.
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